1. Field of the Invention
The present invention relates, generally, to an air intake manifold for an internal combustion engine, and, more specifically, to an intake manifold tuning assembly that efficiently directs air toward the combustion chamber.
2. Description of the Related Art
Internal combustion engines known in the related art may generally include, among other basic components, an air intake manifold and an engine block having one or more cylinders and one or more pistons supported for reciprocal movement in each cylinder. The air intake manifold receives air from a throttle body and directs the air into one or more plenums. Typically, the air intake manifold includes two plenums each having runners that direct air toward alternating cylinders along the engine's firing sequence. By way of example, in a six cylinder engine, the runners would direct air from one plenum to cylinders 1, 3 and 5 and the runners from the other plenum would direct air to cylinders 2, 4 and 6.
At least one intake valve is disposed between the runner and the cylinder to regulate air induction into the combustion chamber. More specifically, during the downward stroke of the piston, the intake valve is open and air is drawn from the runner into the cylinder. Subsequently, the intake valve closes as the piston travels along an upward stroke where the air within the combustion chamber is compressed and combusted. This process is repeated within each cylinder along firing order. However, as the intake valve closes, air within the runner continues to rush toward the cylinder, which creates an increase in air pressure. The difference in pressure between the air in the runner and the air within the plenum causes a disturbance that results in undesirable noise, vibration and harshness (“NVH”) within the engine.
To address this problem, conventional tuning assemblies have been employed to control the flow path of air within the air intake manifold. Generally speaking, a conventional tuning assembly includes a valve that equalizes the air pressure between the two plenums, thereby reducing the likelihood of a disturbance that results in NVH. However, conventional tuning assemblies generally consume a large area (“footprint”) within the engine compartment which is undesirable in the highly competitive industry of automobile manufacturing.
In addition to the constant motivation within the automobile industry to reduce the size of components within the engine compartment, there is an ongoing need to improve engine performance. While conventional tuning assemblies are directed toward equalizing pressure differences, they provide only de minimus improvement with regard to engine performance. More specifically, it is known that increased air density within the combustion chamber will provide improved combustion efficiency and greater engine performance. However, most conventional tuning assemblies merely provide a “blow-by” valve, which passively directs air between the plenums when the pressure difference exceeds a predetermined range. Other conventional tuning assemblies are known to include a power-actuated valve that transfers air between the plenums based on a predetermined set of values corresponding to pressure change, temperature, engine speed, or the like. Such power-actuated assemblies generally suffer from the above-noted disadvantages, namely a large footprint.
Thus, while the pressure equalization between plenums offered by conventional tuning assemblies may provide for a reduction in NVH, they do not effectively utilize the increased air pressure to improve engine performance. More specifically, conventional tuning assemblies do not effectively provide for the efficient redirection of pressurized air toward the next combustion chamber in the firing order for increased engine torque, especially at lower engine speeds. Rather, due to the travel distance of pressurized air from one runner through the plenums and into another runner required by known tuning assemblies only a negligible amount of the pressurized air reaches the next combustion chamber along the firing order.
As a result, there is an ongoing need in the art to improve the induction of air from the intake manifold to the combustion chamber to increase the efficiency of an internal combustion engine, in general. Specifically, there is an ongoing need for an intake manifold tuning assembly that provides a streamlined path through which pressurized air is directed toward consecutive cylinders in the firing order for increased torque output at lower engine speeds. There is also a need in the art for an intake manifold tuning assembly that actively regulates the flow path of air to cylinders for improved torque output while reducing its footprint within the engine compartment.